Bleeding is a common reason for hospitalization and out-patient treatment, particularly in older individuals. Disease or trauma can cause a hemorrhage at virtually any location in the body. Bleeding through the skin is easily identified, since it is clearly visible. However, bleeding within an internal cavity or organ of the body can be much more difficult to identity. As such, critical treatment may delayed as time is spent attempting to localize the intern hemorrhage.
Internal bleeding is an important health problem. Approximately 1 in 5 people will experience at least one episode of significant internal bleeding during their lifetime About half of these episodes are due to bleeding from the colon. The most common cause of colonic bleeding is diverticulosis. Approximately sixty-five percent (65%) of persons develop this condition by age eighty-five. Fifteen percent (15%) of these people, or approximately ten percent (10%) of the entire population will experience significant bleeding as a result.
Many diagnostic techniques now exist to localize an area of internal hemorrhage. These techniques include endoscopy, angiography and nuclear medicine scans. Endoscopy involves the placing of an optical scope into a body orifice such as the esophagus stomach or large bowel. Once a bleeding site is visualized, treatment is often possible using well known techniques such as cauterization or banding. In general, this technique requires that active bleeding occur during the viewing procedure. Bleeding sites may be difficult to identify because of obscuration by blood and the fact that certain regions of the bowel and most internal organs are inaccessible to scopes.
Angiography is an invasive procedure involving the passage of a catheter into the patient's aorta through an entry site, usually in the leg. Dye is injected from the end of the catheter when the catheter is located adjacent to vessels in which bleeding is likely occurring. The dye pools in an area of active bleeding, producing a characteristic blush which can be seen using an X-ray camera. There are many disadvantages of this technique. The dye can cause reactions within the body which can cause kidney failure or even death. Serious bleeding can occur at the site through which the catheter is inserted, and at times this requires an operation to repair. In addition, high doses of X-rays are required to perform this test.
Finally, nuclear medicine scan involves the injection, into the patient's blood stream, of a radioactive marker which attaches to red blood cells. The cells are traced to an active bleeding site using remote scanners sensitive to radiation.
Note that each of the diagnostic tests described above require active bleeding to reveal the presence of an internal hemorrhage. It is often the case that by the time the diagnostic tests are performed, the clot produced by the body is successful at stopping the bleeding, so the test does not provide useful information. Without definitive treatment of the bleeding source about half of these patients will experience recurrent hemorrhage. This is a dangerous situation because the bleeding may occur at any time, even after the patient has left the hospital. The ability to localize the source would allow definitive treatment in many cases and greatly reduce the potential harm caused by bleeding. In cases of particularly severe hemorrhage, the inability to accurately localize a bleeding site may mean that the surgery required to correct it must be much larger in scale than would be required if the bleeding source were well known. The disadvantage to a larger operation are clear. It increases time and costs, increases complications and requires a longer recovery time. For example, if a patient has a life-threatening bleeding condition in the colon, inability to accurately define the region necessitates removal of the entire colon. Conversely, if localization were possible, the patient might lose only one quarter of the entire colon. The latter operation is shorter, simpler and the patient suffers no substantial disability following the operation.
Accordingly, it is an object of this invention to provide a method for localizing an internal bleeding site/hemorrhage that does not require substantial and invasive procedures or internal visible observations. This invention recognizes a consequence of the bleeding, the clot formed by the body at the site. This clot is produced during active bleeding and persists after the bleeding is stopped. This method should enable a bleeding site to be located regardless of whether the site is bleeding actively or is clotted. The method should allow localization with a high degree of accuracy under a variety of conditions.